語言的區分條件可以包括音韻、詞彙、構詞及語法方面的現象。觀察泰雅語與賽德語的音韻差異有六條,但泰雅語的萬大方言卻有四個音韻條件興賽德語相合,因此只剩下兩條勉強可用來區分泰雅語與賽德語。這兩種語言的詞彙差異遠比音韻的差異顯著。在約800個詞項當中,萬大有214個興其他泰雅方言相同,卻只有11個興賽德語相同。此外,萬大有50個獨特的詞項,跟這兩種語言都不同。因此,詞彙的證據顯示萬大爲泰雅方言,殆無疑問。 土田滋先生曾提出三個條件來區分泰雅語的賽考利克方言羣興澤敖利方言羣。包括部分的音韻、構詞、詞彙的差異。本文支持他的觀點並且舉出更多的例證,包括22個詞項以示賽考利克、澤敖利、賽德語三者的不同。至於語法的不同,就有待進一步的研究了。
Three types of linguistic criteria for classifying the Atayalic dialect group have been examined: (1) phonological, (2) lexical and (3) morphological. Lexical, evidence is most abundant and decisive. The, major evidence presented in this paper is lexical. Palnawan, an Atayal dialect, shares most of the phonological features of Sediq rather than Atayal. However, it has essentially the same basic vocabulary as the other Atayal dialects. Furthermore, lexical differences between Squliq, C?uli? and Sediq are also noted in the paper. Not much syntactic data is, available for the entire group. This is a large open field for. further investigation.